High-dielectric low-loss dielectric material and preparation method thereof

Abstract

This invention discloses a high-dielectric-weight, low-loss dielectric material and its preparation method, relating to the field of electronic ceramic materials technology. It comprises the following components in molar amounts: 60-90 moles of barium titanate, 10-40 moles of potassium tantalate, 0.2-3 moles of bismuth oxide, 0.6-4 moles of titanium dioxide, 0.1-0.8 moles of niobium pentoxide, 0.1-0.5 moles of manganese carbonate, and 0.2-0.6 moles of vanadium pentoxide. The high-dielectric-weight, low-loss dielectric material disclosed in this invention exhibits a high dielectric constant, low dielectric loss, and high electric field strength resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic ceramic materials, and particularly relates to a high-dielectric low-loss dielectric material and a preparation method thereof. Background Art

[0002] In recent years, due to the huge demand for energy and the rapid development of microelectronics technology, the search for high-dielectric materials for electronic and energy storage devices has attracted extensive attention in the industry. However, high-dielectric materials on the market often have relatively large dielectric losses. As is well known, high dielectric losses often lead to problems such as device or circuit heating, unstable operation, or signal attenuation, thus severely restricting the industrial production of ceramics. It can be seen that it is crucial to further reduce the dielectric loss while maintaining the high dielectric constant.

[0003] Lead-free barium titanate-based ceramic dielectric materials are one of the commonly used dielectric materials at present. However, the dielectric constant of this material is usually lower than 4000, with poor temperature stability, high sintering temperature, and various performance aspects such as losses cannot be balanced. It is necessary to add additives to modify this dielectric material to increase the dielectric constant and reduce the dielectric loss.

[0004] Potassium tantalate (KTaO3) single crystal has a stable cubic structure and can be used to make laser modulators, digital deflectors, and semiconductor devices. Since its crystal has no phase change within the temperature range from absolute zero to the melting point (1645K), it can be seen that its stability is excellent. The dielectric constant of single crystal potassium tantalate can reach 4400+, and theoretically, it has the feasibility of being used as an additive to increase the dielectric constant and reduce losses in lead-free barium titanate-based ceramic dielectrics.

[0005] To solve the above problems, the Chinese invention patent with the authorization announcement number CN106145932B discloses a dielectric material for a multilayer ceramic capacitor with a high dielectric constant and a preparation method thereof. The composition chemical formula of the dielectric material is (1-n)Ba m , 0.48 , 1-m , 3-n , <​​​​​​​​​​​​​​​​​​​It is evident that developing a high-dielectric-low-loss dielectric material with high dielectric constant, low dielectric loss, and high electric field strength resistance, along with its preparation method, meets market demand, has broad market value and application prospects, and is of great significance for promoting the development of the dielectric materials field. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high dielectric low loss dielectric material with high dielectric constant, low dielectric loss, and high electric field strength resistance, as well as its preparation method.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a high dielectric and low loss dielectric material, comprising the following components in molar amounts: 60-90 moles of barium titanate, 10-40 moles of potassium tantalate, 0.2-3 moles of bismuth oxide, 0.6-4 moles of titanium dioxide, 0.1-0.8 moles of niobium pentoxide, 0.1-0.5 moles of manganese carbonate, and 0.2-0.6 moles of vanadium pentoxide.

[0009] Another object of the present invention is to provide a method for preparing the high dielectric low loss dielectric material, comprising the following steps:

[0010] Step S1: Pre-preparation of potassium tantalate: Tantalum pentoxide and potassium carbonate powder are mixed, ball-milled, dried and calcined using anhydrous ethanol as the dispersion medium, and then sieved and granulated to obtain KTO powder.

[0011] Step S2, Preparation of dielectric material: Barium titanate, KTO powder obtained in step S1, bismuth oxide, titanium dioxide, niobium pentoxide, manganese carbonate, and vanadium pentoxide are mixed and ball-milled using deionized water as the dispersion medium. The mixture is then dried, pulverized, passed through a standard sieve, granulated, and pressed into tablets. The tablets are then debinded and sintered to obtain the dielectric material.

[0012] Preferably, the molar ratio of tantalum pentoxide and potassium carbonate powder in step S1 is 1:1.05.

[0013] Preferably, the ball milling time in step S1 is 6-8 hours.

[0014] Preferably, the drying time in step S1 is 2-6 hours and the temperature is 85-120℃.

[0015] Preferably, the calcination temperature in step S1 is 1050-1120℃ and the time is 3-5h.

[0016] Preferably, the D50 of the KTO powder in step S1 is ≤0.5um.

[0017] Preferably, the ball milling time in step S2 is 4-10 hours.

[0018] Preferably, the pressure for tableting in step S2 is 200-400 MPa.

[0019] Preferably, the particle size D50 after granulation in step S2 is ≤0.5um.

[0020] Preferably, the temperature for discharging adhesive in step S2 is 500-600℃, and the heat preservation time is 2-6h.

[0021] Preferably, the sintering temperature in step S2 is 1150-1250℃, and the holding time is 2-6h.

[0022] Due to the application of the above technical solutions, the present invention has the following beneficial effects: Through the rational selection of component formulation and preparation process parameters, the present invention enables the components to work together synergistically, giving the finished product advantages such as low dielectric loss, high dielectric constant, and high electric field strength resistance. The introduction of high dielectric constant potassium tantalate into barium titanate solves the defects of its use alone, effectively reducing dielectric loss while ensuring a high dielectric constant. The raw materials used do not contain elements harmful to the environment and humans such as lead, cadmium, mercury, and arsenic, making the preparation and use process safer and more environmentally friendly. Detailed Implementation

[0023] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0024] Example 1

[0025] A high-dielectric-low-loss dielectric material is made of the following components in molar amounts: 60 moles of barium titanate, 38.8 moles of potassium tantalate, 0.2 moles of bismuth oxide, 0.6 moles of titanium dioxide, 0.1 moles of niobium pentoxide, 0.1 moles of manganese carbonate, and 0.2 moles of vanadium pentoxide.

[0026] A method for preparing the high-dielectric-low-loss dielectric material includes the following steps:

[0027] Step S1: Pre-preparation of potassium tantalate: Tantalum pentoxide and potassium carbonate powder are mixed, ball-milled, dried and calcined using anhydrous ethanol as the dispersion medium, and then sieved and granulated to obtain KTO powder.

[0028] Step S2, Preparation of dielectric material: Barium titanate, KTO powder obtained in step S1, bismuth oxide, titanium dioxide, niobium pentoxide, manganese carbonate, and vanadium pentoxide are mixed and ball-milled using deionized water as the dispersion medium. The mixture is then dried, pulverized, passed through a standard sieve, granulated, and pressed into tablets. The tablets are then debinded and sintered to obtain the dielectric material.

[0029] The molar ratio of tantalum pentoxide and potassium carbonate powder in step S1 is 1:1.05; the ball milling time in step S1 is 6 hours; the drying time in step S1 is 3 hours and the temperature is 100°C; the calcination temperature in step S1 is 1050°C and the time is 3 hours; the D50 of the KTO powder in step S1 is ≤0.5 μm.

[0030] The ball milling time in step S2 is 4 hours; the pressing pressure in step S2 is 200 MPa; the particle size D50 after granulation in step S2 is ≤0.5 μm; the debinding temperature in step S2 is 550°C and the holding time is 2 hours; the sintering temperature in step S2 is 1250°C and the holding time is 2 hours.

[0031] Example 2

[0032] A high-dielectric-low-loss dielectric material is made of the following components in molar amounts: 70 moles of barium titanate, 26.8 moles of potassium tantalate, 1 mole of bismuth oxide, 1.5 moles of titanium dioxide, 0.2 moles of niobium pentoxide, 0.2 moles of manganese carbonate, and 0.3 moles of vanadium pentoxide.

[0033] A method for preparing the high-dielectric-low-loss dielectric material includes the following steps:

[0034] Step S1: Pre-preparation of potassium tantalate: Tantalum pentoxide and potassium carbonate powder are mixed, ball-milled, dried and calcined using anhydrous ethanol as the dispersion medium, and then sieved and granulated to obtain KTO powder.

[0035] Step S2, Preparation of dielectric material: Barium titanate, KTO powder obtained in step S1, bismuth oxide, titanium dioxide, niobium pentoxide, manganese carbonate, and vanadium pentoxide are mixed and ball-milled using deionized water as the dispersion medium. The mixture is then dried, pulverized, passed through a standard sieve, granulated, and pressed into tablets. The tablets are then debinded and sintered to obtain the dielectric material.

[0036] The molar ratio of tantalum pentoxide and potassium carbonate powder in step S1 is 1:1.05; the ball milling time in step S1 is 6.5 h; the drying time in step S1 is 3 h at a temperature of 100 °C; the calcination temperature in step S1 is 1070 °C for 3.5 h; and the D50 of the KTO powder in step S1 is ≤0.5 μm.

[0037] The ball milling time in step S2 is 6 hours; the pressing pressure in step S2 is 250 MPa; the particle size D50 after granulation in step S2 is ≤0.5 μm; the debinding temperature in step S2 is 550°C and the holding time is 2.5 hours; the sintering temperature in step S2 is 1230°C and the holding time is 3 hours.

[0038] Example 3

[0039] A high-dielectric-low-loss dielectric material is made of the following components in molar amounts: 75 moles of barium titanate, 19.75 moles of potassium tantalate, 1.5 moles of bismuth oxide, 2.5 moles of titanium dioxide, 0.5 moles of niobium pentoxide, 0.35 moles of manganese carbonate, and 0.4 moles of vanadium pentoxide.

[0040] A method for preparing the high-dielectric-low-loss dielectric material includes the following steps:

[0041] Step S1: Pre-preparation of potassium tantalate: Tantalum pentoxide and potassium carbonate powder are mixed, ball-milled, dried and calcined using anhydrous ethanol as the dispersion medium, and then sieved and granulated to obtain KTO powder.

[0042] Step S2, Preparation of dielectric material: Barium titanate, KTO powder obtained in step S1, bismuth oxide, titanium dioxide, niobium pentoxide, manganese carbonate, and vanadium pentoxide are mixed and ball-milled using deionized water as the dispersion medium. The mixture is then dried, pulverized, passed through a standard sieve, granulated, and pressed into tablets. The tablets are then debinded and sintered to obtain the dielectric material.

[0043] The molar ratio of tantalum pentoxide and potassium carbonate powder in step S1 is 1:1.05; the ball milling time in step S1 is 7 hours; the drying time in step S1 is 3 hours and the temperature is 100°C; the calcination temperature in step S1 is 1090°C and the time is 4 hours; the D50 of the KTO powder in step S1 is ≤0.5 μm.

[0044] The ball milling time in step S2 is 7 hours; the pressing pressure in step S2 is 300 MPa; the particle size D50 after granulation in step S2 is ≤0.5 μm; the debinding temperature in step S2 is 550°C and the holding time is 3 hours; the sintering temperature in step S2 is 1220°C and the holding time is 3.5 hours.

[0045] Example 4

[0046] A high-dielectric-low-loss dielectric material is made of the following components in molar amounts: 85 moles of barium titanate, 7.4 moles of potassium tantalate, 2.5 moles of bismuth oxide, 3.5 moles of titanium dioxide, 0.7 moles of niobium pentoxide, 0.4 moles of manganese carbonate, and 0.5 moles of vanadium pentoxide.

[0047] A method for preparing the high-dielectric-low-loss dielectric material includes the following steps:

[0048] Step S1: Pre-preparation of potassium tantalate: Tantalum pentoxide and potassium carbonate powder are mixed, ball-milled, dried and calcined using anhydrous ethanol as the dispersion medium, and then sieved and granulated to obtain KTO powder.

[0049] Step S2, Preparation of dielectric material: Barium titanate, KTO powder obtained in step S1, bismuth oxide, titanium dioxide, niobium pentoxide, manganese carbonate, and vanadium pentoxide are mixed and ball-milled using deionized water as the dispersion medium. The mixture is then dried, pulverized, passed through a standard sieve, granulated, and pressed into tablets. The tablets are then debinded and sintered to obtain the dielectric material.

[0050] The molar ratio of tantalum pentoxide and potassium carbonate powder in step S1 is 1:1.05; the ball milling time in step S1 is 7.5 h; the drying time in step S1 is 3 h at a temperature of 100 °C; the calcination temperature in step S1 is 1110 °C for 4.5 h; and the D50 of the KTO powder in step S1 is ≤0.5 μm.

[0051] The ball milling time in step S2 is 9 hours; the pressing pressure in step S2 is 350 MPa; the particle size D50 after granulation in step S2 is ≤0.5 μm; the debinding temperature in step S2 is 550°C and the holding time is 3.5 hours; the sintering temperature in step S2 is 1180°C and the holding time is 4 hours.

[0052] Example 5

[0053] A high-dielectric-low-loss dielectric material is made of the following components in molar amounts: 90 moles of barium titanate, 1.1 moles of potassium tantalate, 3 moles of bismuth oxide, 4 moles of titanium dioxide, 0.8 moles of niobium pentoxide, 0.5 moles of manganese carbonate, and 0.6 moles of vanadium pentoxide.

[0054] A method for preparing the high-dielectric-low-loss dielectric material includes the following steps:

[0055] Step S1: Pre-preparation of potassium tantalate: Tantalum pentoxide and potassium carbonate powder are mixed, ball-milled, dried and calcined using anhydrous ethanol as the dispersion medium, and then sieved and granulated to obtain KTO powder.

[0056] Step S2, Preparation of dielectric material: Barium titanate, KTO powder obtained in step S1, bismuth oxide, titanium dioxide, niobium pentoxide, manganese carbonate, and vanadium pentoxide are mixed and ball-milled using deionized water as the dispersion medium. The mixture is then dried, pulverized, passed through a standard sieve, granulated, and pressed into tablets. The tablets are then debinded and sintered to obtain the dielectric material.

[0057] The molar ratio of tantalum pentoxide and potassium carbonate powder in step S1 is 1:1.05; the ball milling time in step S1 is 8 hours; the drying time in step S1 is 24 hours and the temperature is 95°C; the calcination temperature in step S1 is 1120°C and the time is 5 hours; the D50 of the KTO powder in step S1 is ≤0.5 μm.

[0058] The ball milling time in step S2 is 10 hours; the pressing pressure in step S2 is 400 MPa; the particle size D50 after granulation in step S2 is ≤0.5 μm; the debinding temperature in step S2 is 600°C and the holding time is 4 hours; the sintering temperature in step S2 is 1150°C and the holding time is 5 hours.

[0059] Comparative Example 1

[0060] A high-dielectric-low-loss dielectric material is basically the same as that in Example 1, except that barium titanate is used instead of KTO powder in equal amounts.

[0061] Comparative Example 2

[0062] A high-dielectric-low-loss dielectric material is basically the same as that in Example 1, except that manganese carbonate and vanadium pentoxide are not added.

[0063] To further illustrate the beneficial technical effects of the high-dielectric-low-loss dielectric materials involved in the various embodiments of the present invention, relevant performance tests were conducted on the high-dielectric-low-loss dielectric materials involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test methods are as follows: Silver was brushed on both sides of the prepared high-dielectric-low-loss dielectric material, and sintered at 850°C for 20 min to prepare silver electrodes. The dielectric properties of the ceramic material were tested using a Cuiliient 4294A precision impedance analyzer and an E4980A LCR meter, respectively. The electric field strength Eb value was obtained by applying a high voltage DC voltage to the ceramic sample in silicone oil at room temperature using a Keithley 2410 digital source meter for IV testing.

[0064] Table 1

[0065]

[0066] As can be seen from Table 1, the high dielectric and low loss dielectric materials involved in the embodiments of the present invention have a larger dielectric constant, lower dielectric loss, and higher electric field strength than the comparative product. The combined use of KTO powder, manganese carbonate, and vanadium pentoxide has a beneficial effect on improving the above properties.

[0067] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-dielectric-weight, low-loss dielectric material, characterized in that, It is made from the following components in molar amounts: 60-90 moles of barium titanate, 10-40 moles of potassium tantalate, 0.2-3 moles of bismuth oxide, 0.6-4 moles of titanium dioxide, 0.1-0.8 moles of niobium pentoxide, 0.1-0.5 moles of manganese carbonate, and 0.2-0.6 moles of vanadium pentoxide.

2. A method for preparing a high-dielectric-low-loss dielectric material according to claim 1, characterized in that, Includes the following steps: Step S1: Pre-preparation of potassium tantalate: Tantalum pentoxide and potassium carbonate powder are mixed, ball-milled, dried and calcined using anhydrous ethanol as the dispersion medium, and then sieved and granulated to obtain KTO powder. Step S2, Preparation of dielectric material: Barium titanate, KTO powder obtained in step S1, bismuth oxide, titanium dioxide, niobium pentoxide, manganese carbonate, and vanadium pentoxide are mixed and ball-milled using deionized water as the dispersion medium. The mixture is then dried, pulverized, passed through a standard sieve, granulated, and pressed into tablets. The tablets are then debinded and sintered to obtain the dielectric material.

3. The method for preparing the high-dielectric-low-loss dielectric material according to claim 2, characterized in that, The molar ratio of tantalum pentoxide and potassium carbonate powder in step S1 is 1:1.

05.

4. The method for preparing the high-dielectric-low-loss dielectric material according to claim 2, characterized in that, The ball milling time in step S1 is 6-8 hours.

5. The method for preparing the high-dielectric-low-loss dielectric material according to claim 2, characterized in that, The drying time in step S1 is 2-6 hours, and the temperature is 85-120℃.

6. The method for preparing the high-dielectric-low-loss dielectric material according to claim 2, characterized in that, The calcination temperature in step S1 is 1050-1120℃, and the time is 3-6h; the D50 of the KTO powder in step S1 is ≤0.5um.

7. The method for preparing the high-dielectric-low-loss dielectric material according to claim 2, characterized in that, The ball milling time in step S2 is 4-10 hours.

8. The method for preparing the high-dielectric-low-loss dielectric material according to claim 2, characterized in that, The pressure for tableting in step S2 is 200-400 MPa; the particle size D50 after granulation in step S2 is ≤0.5 μm.

9. The method for preparing the high-dielectric-low-loss dielectric material according to claim 2, characterized in that, The temperature for discharging adhesive in step S2 is 500-600℃, and the holding time is 2-6 hours.

10. The method for preparing the high-dielectric-low-loss dielectric material according to claim 2, characterized in that, The sintering temperature in step S2 is 1150-1250℃, and the holding time is 2-6h.

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